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SWSL Teleconference Notes
Thursday Feburary 12, 2004
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Attendees
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Karl Aberer
Daniela Berardi
Richard Goodwin
Benjamin Grosof
Michael Kifer
Sheila McIlraith (scribe)
Bijan Parsia
David Martin
Frank McCabe
Terry Payne
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Summary of Action Items:
BP: Will set up IRC log->scribe notes for next time
DM: Will query list regarding possible new telecon time
1pm EST, Thursdays
DM: Will investigate whether the SWSL F2F location can
be changed a this late date
TP: Will scribe next week
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Summary of Topics Discussed:
Admin:
- using IRC chat to generate scribe notes
- scribe notes from 2 weeks ago
- telecon time
- location of SWSL F2F
Foundational:
- ensuring we have impact, given other growing efforts (w3c, oasis, etc.)
Technical:
- WSDL Typing: including an OWL component into imminent WSDL document?
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FRANK MCCABE
DM: Welcome to Frank McCabe who joins SWSL for the first time!
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FACILITATING SCRIBE NOTES
Proposal for different way to produce scribe notes
IRC log -> scribe notes -> edit it later
more than one person helping with notes
ACTION ITEM: Bijan will set up something for next time
unix/linux: xchat (all you need, oldest most mature, poorer ui, best for
firewalls)
mozilla has the chat client built in (will do in a pinch)
(hundreds)
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NOTES FROM 2 WEEKS AGO
DM: Admin:
- Terry posted minutes from 2 weeks ago
TP: Please check minutes. If they're OK Terry will ensure they're
posted to the interest group.
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CHANGING TIME OF TELECON
DM: We all have some European & Cdn voices causing trouble about the
schedule. DM open to a round of revisitng the schedule, since
it's late for Eruopean folks.
MK: Can we move just the time rather than the day.
BP: I'd do Tuesdya morning in a hot second.
***** Static **** Lost connection ***********
BP: Normally WSDL telecons 11-12:30 EST
Can start at 1pm EST (1.5 hrs earlier than now)
MK: Will it help Europeans?
KA: Definitely yes!
MK: Any objections from those present?
All: No objections to Thursday.
6pm England
7pm in Central Europe
1pm EDT
10am PDT
DM: ACTION: Will send message regarding possible new time to list
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TIME AND LOCATION OF F2F
DM: F2F unlikely to be changed at this time.
Exact schedule:
F2F Sunday and Monday following WWW
SWSI F2F: May 23, 24
DAML PI Meeting May 25 - ???
VARIOUS:
Discussion of expenses, whether to go to Bell Labs
Discussion of how bad schedule and cost is.
Try very hard not to co-locate it with DAML in the future.
TP: Come to Europe next time
DM: Time for more conversation on SWSL all
KA: Not participating that much because Fensel's European projects starting
up. Proposes stronger involvement from europeans. Invite more
people from these projects.
MG: Thought that it was meant to be that way.
DM: Agrees w/ KA
- pursue more Euro contacts
KA: KnOWLedgeWare sponsored workhsop in Crete will be in June.
(KnOWLedgeWare is the follow-on to OntoWeb)
MK: Probably a little too late.
BP: Suggest the chairs take an action item to investigate whether too
late for this time around.
DM: ACTION: Will talk to DAML people about whether it's too late to
more meeting
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ENSURING IMPACT: ESTABLISHING/MAINTIANING CONNECTIONS & INFLUENCE
BG: Write letter to W3C and Oasis (WS security) about formal cooperation with
ws choreography.
we need to think about our strategy re: coordination & cooperation w/
other efforts.
BP: Agree, WSI too.
BG: Previously we decided to pack committeees (Bijan and Katia have been
doing this). There are several other groups that we have little
communication w/ who are tromping on our turf.
Steve Ross-Talbot says we could do a lot ot raise our profile.
BP: insight into ws choreography:
Jim Hendler on it, now subbed by grad student
WSC still floundering
Subset interested in adding semantics (value add) but don't have
ton of expertise. Steve Ross Talbot always encouraging.
FM Main issue w/ Choreogrpahy work is microsoft
Specific suggestions
1. Outreach: If we wnat to promote, must go to them
a) larger membership. encourage to also be part of X
b)Focus on core values: what is the fulcrum about which everythign will
turn and focus on this.
BG: many ways to do outreach. Big financial step for academics because
of membership costs. Thus, one way to do is to make outbound activities
inbound. E.g., ask people to come in to talk to us
(e.g. guest appearances: Frank Leyman, Rania, etc.)
Will motivate them to read our stuff and vice versa.
BP: Be more active about organizing responses to public documents.
E.g. have impact at key times.
BG: Organize our contact lists. Who we know at more or less personal
levels.... Know who to ping periodically to find out when these
committtees are coming up for air.
BP: let's move on. I want to talk about WSDL Typing.
DM: Right
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WSDL TYPING
BP:
Possible augmentation to WSDL Spec.
Do b4 last call.
Last call wil be May
Trying to finalize tech plenary in march. Better to do now.
Using OWL as type system for WSDL fairly complex. MAy take time to come
to consensus about this.
DM: Let's move on to this.
BP: Has everyone followed the thread on public_swsig? Here's a precis
In WSDL you have
- interfaces (use to be ??)
they have
- operations (a msg exhcnage paetter in-out in-out-out-out
- message types for each posn in the message exchagne patter
e.g., out and msg must conform to msg schem pattern
in wsdl no execution semantics (e.g, what causes, etc.)
now, built into wsdl, can associate slot to a particular XML schema element
declaration e.g., that top level tag has to be address, at least one
street address sub element, state option, etc.
In appendicies of WSDL some nonmormative
DTD
Relax.... Schemas
To do must
- extend type element (show to embed or reference)
- add ability to reference from descriptions of messages in the operation.
Question: Do we want to push for nonnomrative or normative to describe
with OWL typing?
Might be a little problematic
Basically we need to decide:
- a particular message is described by OWL class, must use uninteresting OWL
classes e.g., messages. not places, people. There is a representational gap.
There is also the Decker problem: It's very hard to know, given the way
OWL works, how much info and whether you have all the info, before invoking
a service, if you specify with OWL assertions. It's easy to say the
message has to be member of class "invoice", and invoice is restricted in
certain ways. ...need to know that there is a specific address, trying
to invoke the service and failing.
MK/BP: It's exactly relates to our discussion w/ Pat Hayes.
pblm OWL doesn't have typing in the way pgming languages have typing
Need something else. need to sya an object *must* have this attribue
and this is all you havea
BG: This has come up over and over again.
1) Issue of "closing off"
2) Big difference between an existential that's unbound and one that
is bound
2 biggest problems that makes it difficult to validate in OWL.
If we propose that OWL is allowed optionally, people won't be hapy using
until some of these fundamental shortcmings are addressed.
BP: Soem agree with you, others think it could be gotten in and is worth
it.
If we came up with a solution. It's an opportunity over the next 2 years
that won't come around again for another 4.
BG: Pragmatic: Push to have it in, but lower people's expectations about
how it's going to be used. Let's have it be part of the specs, facilitate
experimenting with it in R&D
Despite shortcomings, let's include, even if it isn't going to be used
immediately.
BP: There is the place in the spec about how to add typing.
I ahve problem that I like to describe everything that is wrong
with an approach.
BG: Why do you say we can get it in?B
BP: Some people want it.
Thinks we can come up w/ a solution.
BG: 2 approaches
1) Extend OWL to change into a datatyping languge
2) Turn into an auxilliary language. Don't have to worry abot
"closing off" issue. Can just sell this as a way to describe
extra stuff.
DM: WS - I'm willing to take as input a URI or serialized instance
anything that gets classified as X. Why should WSDL stand in the
way of such service providers.
From client side, want to know what client requires from you before
you start out. Maybe I don't know my SSN
Fujisu likes to do this. Treat OWL as if it's a typing language -- do
levels of closure. Hard to argue that that's a useful thing.
FM: Bijan is OWL as a type defn language the best and most appropriate way
of put types into WS description.
To do a proper typing system is a significant amt of work.
Building a type system is not trivial (I've done it).
Get expressibility right, all rest -- significantly amt of effort.
BP: I don't want to build a type system.
FM: Yes you are. You have to do fair amt of work.
- Does any one want to do
- is that the optimal entry point for OWL or semantics in WSDL
I'm not sure it is. we already ahve good typing languages. If we
constrain OLW to be a good typing language, maybe we lose the other
good stuff.
BP: Agreed might want to make assertions about preconditions and effects
of services, but maybe not for describing the type
FM: There are more juicy topics.
BG: What would we lose.
To do tping, need to be able to close off.
....
BP: feeling right now that WSDL is very minimal, but in my f2f, etc
see that people are thinking of it as a foundatio for more expressive
descriptions
In WSDL, operations aren't processes.
processes are heavywieight things - either a piece of software, affects
the world in some way, etc.
Fervor that an operation in wsdl isn't one of those things.
issue of typing msgs dovetails w/ this.
need to think about how we're going to do this:
all operations are processes?
FM: I would push back on this. I think it's easy to think of operations
as processes, but it's not the way I like to. where I'm coming from,
the signals interesting events.
BP: <Clarification>
DM: Way we talk about atomic processes, we don't talk about the execution
of an atomic process, therefore not incompatible
FM: Imagine as speech acts...
that view of services is very consistent w/ WSA and how the service
oriented architecture will end up.
BP: I don't think of
MG: This is exaclty what we should be talking about with the conceptual
model. what do we mena by process, operation, etc.
BP: I think if we fleshed out what we were thinking of, they would be
distinct.
Having
BP: Consuming objects and producing objects
FM that's the core of it. The RPC inheritance howing throught. Not
consistent w/ the document centric view.
BP We could layer a more process oriented view on top of WSDL
What is our core basic conceptuatl unit that we're thinking about?
Is it something more and there is always something more to say.
BG: If this is the low end, what's our stake in it?
We hae a stake because what maps at a lower lvel
Goes far beyond what the messages that are exchanged about it are.
There are some major side effects. we want to have scope to describe
those types of characterisitcs that go well beyond its msg pattern.
Isn't necessarily choreography scoce either.
It's an atomic process to say "hit the button", but it has side
effects
DM: Do want to go back to your initial question.
Do we want to use an OWL class to be used as a the type of a message.
If answer is no, then troubling - OWL is doomed.
I think we can do something, but ....
No no...there is no problem with retrieving instances of a type
if I have a KB, assertions, ontologies "is Bijan a person", can
look at it and say yes/no
here is a class, find all members.
but just doing that isn't that useful for describing service interfaces.
DM same problem w/ any OWL query server.
if they're going to be able to function then
if query is "who are all the people", "how many people there are?"
All that is distinct from formulating, "all of the known first names
of the people in the db.
The query is differnt -- specifies what you want, you get bindigns.
If we had the right kind of query language in OWL, then the types
BG: It's not just the pblm w/ the query lang, but it's the intended interp.
Competing purist veins that closing off is bad!
what you're talking about w/ the query langauge is "closing off"
- co ground
- co existentially quantified....
BP: I thought of a cheesy way...I'll put it in a message...
Yes there are issues...there are big issues.
you wnat to say I want an instance of this particular known attribute
Made possible, or take it
BP: Initial proposal: minimalistic thing
Other: provide some sort of solution that allows at least for rdf data
that provides some template or constraitnt - maps to XML schema or...
I think it's a pretty important issue to be able to describe the interfae
constraings
QUSTIO: DOes the committee want to take it on.
BG: joint committee worked on DQL, but there wasn't pull except for DL
theorem provers. One way to proceed is to basically do soemthing that
defines a type in terms of DQL stuff.
Another wya: RDF data access group. they'll have to deal with schema
template..... I don't think all the other fish that we have to fry
that we shoudl be the ones in charge of it, but a lot depends on timing.
window to push for this isshort-temr.
BP: window for core1 spec
mapping to SW will be a separat docuemtn. Certainly addressing this
is part of the scope of that
It would be great to be in last call by may.
BG: The latter would be possible if incubated in the relevant groups
BP:
Propose a more minimal work product for us:
Specify clearly our interst in haveing a solution and some desiderata
so it will become higher profile on these other grups.
Seems reasonable.
BG: treat it as part of our requirements.
suggest one or more techinql approaches that require comments.
DM: Might be possible to put into the wsdl documentation that you
can excahnge messages that have OWL contents provied the syntax
is constrained appropriately.
Look, just define an XML schema that says, you're going to use n triples
and make sure they don't have X, and they have this data te
You can use XML schema to constrain to be ground instances that hve
only certain properties.
Might have problems w/ potential equivalences.
"Just use XML schema to use this"
BG: Don't understand . the only game in town right now is XML Schema
for issues like:
- closing off
- validating
- boundness
- ....
MK: what's wrong with using XML Schema?
DM: Nice to prevserve the functionality of using an OWL class
MK: but XML Schema can refer to OWL and OWL+
BP: I was proposing to use an XML Schema type to constrain the
so you'd be forced to include all and only the ground assertions.
This is different from what MK and BG are proposing.
Right now you can't properly identify
BG: XML Schema is a container and pointing system. It's not a rich language.
Start w/ things pac
view XML schema as a set of constraints on a bunch of OWL assertions.
MK: Yes that's what i was proposing, but the shcema type can only
ALL: Conclusion: we're not settled on what we want to do. we'll have tol
continue to come to consensus.
TP: Volunteers to scribe for next telecons